Noise-dampener for brake drums



Aug. 27, 1935. i s. G. TILDEN NOISE DAMPEN ER FOR BRAKE DRUMS Filed Oct. 17, 1933 II/II/Il/A INVENTOR MA A t-r0 N 3 brake drum, or to a brake drum'during the course Patented Aug. 27, 1935 I OFFICE Noise-smit en Iron BRAKE imUMs smear-1mm, Stewart Manor, L7 Longjsland; N; Applicationbctober ,17"; 1933, serial N6. 693,899

'zlciaims; (o1. res- 218) This invention relates to noise-dampenersfor brake drums and has for, its purpose andobject to provide a simple and inexpensive noise-dampener whichmay be readily applied to an existing of its manufacture Researches in noise-producing qualities of brake drums have-shownthat they act in the na ture of bells or trumpets, in; that the vibrations are amplified bythe shape ofthedrum, and yibrations so set upoften produce a very objection:

able noise on the application of the brakes. Sev

eral attempts havebeen made'toovercomesuch noise-producing vibrations, but the proposed '1 devices have inherent objectionable features, and

while they may to some extent reduce noise, they present other obstacles as, forinstance, the, prer vention of-heat radiation from the, drum, Thisinvention finds-itsembodiment in a dampener placed in sucha positionon the-flange of to require stretching, of the; dampeneiz-upon its application to, thejbrakedrum. Due to the-in,-.,

herent resiliency of the material of which. the;

dampener is composed, thedampener will remain in that-pcsitionin which it is placed; and owing, to the molecular disposition of the, material of,

which the, dampener is composed, astretching of the rubber will so dispose the dampener that it 3 will maintain constant tension against theybrake drum and assume, a predetermined position.

Such stretching or distorting of the, rubberwill, enable the dampenerto be, applied in a certain manneryand for its preferred use, the dampener is pressed against the flare of the drum andgduei to the inherent resiliency of the material, :will maintainpressure against the flare ofgthe brake drum at which point of the brake drumgthe amplitude of the vibrations is greatest; Sufficient mass of materialis provided to accomplish'the object set forth and inherent rotational balance is particularly included, in the improved'dampener.

ener remains atany predetermined partIrof the:

brake drum flange, and-because of this advantagerand its structuralattributesythe .dampener bears towards the flare "or. ;-the brakeiedrumiwheni ment ofmy improvedring, showing the dampen My improved dampener'is simple in structure,

stretched circumferentially thereof, and placed in proximity thereto. v r

;The.invention will be more particularly described hereinafter, embodiments thereof shown outin the appended claims;

In the accompanying drawing Eigure 1 is .aiperspective view of a brake drum such as is well known andin common use, having an embodiment oi ;my' invention applied thereto; v e v figure 2 is a transverse section of the end of the. brake drum, showing the flange andthe flare: asppart thereof, withan embodiment of my inventionapplied thereto; 7. ,s Figure 3,1sa longitudinal section of anembodiment of vmyinventionshown in relation to the surface of, thee brake drum, the dampening ring not being'underltension, that is, the .dampener is not stretched to the brake diameter;

Figure 4 isa similar longitudinal section-show- 1 ing the, dampening ringg unde'r, tension;

,, I'lig i,ire15v is aview showing the functional inter relationship ofthe constituent elements of my improvedr-ing;

,Figure 6,v isa longitudinal section of my improvedaring embraced by a bead formed atthe end of the brake drum, the ring being applied during the course of. manufacture ofthebrake drum; gFigurel is a-sectional' view of another embodiapplication cular, and preferablya unitary, ring composed of 7 rubber or similar material. The ring h'asan ins ternal diameter of smaller dimensionthan that ofits-externa1 diameter, the differencein the diameters beinggreater than the thickness of the material forming :thering. The cross. sectional area of thering-is suchthat it provides a sufli cient masswhich will 'deaclen'the vibrations. The interior diameter cfthe ring'being smaller than the diameter .of the exterior surface. of the drum flange, stretching ofthe ring is requiredin. order to" apply it to the exteriorof"thebralie-drum; and

upon application to the brake drum the ring remains in'its applied position wherever placed due to its inherent resiliency.

The rubber ring is stretched or expanded circumferentiallyon its application around the-periphery .of the drum so that it is held in place thereon by its natural inherent contractibility. As it ismoved against the drum flare in its contracted or tensionedstate, it becomesmore or less distorted from the position inwhich it is; placed so as to fit tightly between the surfaces of the flange and flare, exerting pressure thereon ments shown in the drawing, it'will benoted that thebrake-dr'um lfl has a flange II 'and laterally thereof aflare I 2 ;=and it -will'also be observedthat the resilient ring-has contact with the-flange-= of the brake drum and with the flare I2 -of the flange II.

,resilient ring has such configuration that-whenapplied to the flange of the brake'drum it dis-- In certain of these embodiments-the torts itself in a flared manner'and these-flared portions exert a lateral pressure againstany-ob-' ject in the path'of such lateral pressure The ring I5 of Fig. 3 is clearly shown when distortedin Fig; 4, thecurved sidewallsforming flared-portions, and similarly in the embodiment 1of Fig.= 8,

when-the ring is distorted, -it presents a flared portion,as shown in f I 1 It has been found that thegreates'tamplitude of vibrations is present at the flare" I 2 of thedr umg and therefore the ring-is adapted for a ziplication directly'to the flare,-tl'ius acting in the-nature of a mute and deaden'snoiseso From Figure-21twill be seen thatthe dampener I SpressesQagainst' the inner surface of the flare I2, and also-against? the external surface of the-flange I I-',* a'nd in the embodiment shown, the material of the ring IS covers the fillet I3 of the flare. -The functional; action of the ring is shown diagrammatically in Figure5, wherein the-larger su'rfaceportion I6 abuts against the flare I2 and a smallerporti'on I7 of narrower surface, abuts against the flange !I, the advantage being that the larger surface acts as a' mute, that is deadens'the sound, and

the smaller surface 11 acts onthe flange, allowing as much room as possible ionthe flangefor heat radiation purposes. These functional constituent elements find; their. counterpart-in theembodiment shown in Figures 2 and 3. i

In the preferred embodiment, the, cross sectional configuration of: the ring is such that when circumferentiallystretched its sectional periph j ery is distorted in such a manner as to press the" ring a ainstthe-flare I2, asshown in Figures 2 and 9, and thetendency to do-so'is shown-inFig-- ures4and7. t

' The cross sectional configuration" of'ring l5 of Fig. 3, is such that a'straightsurfa'ce -I8 corre sponds to the innermost-circumference of the ring, and adjacent theretoisa'curved'portion I9,- so that when the ring is applied totheflangegl I,

the curvedportion I 9 will fit snugly into-the fillet I3 of the flare, for whichpurpose'zthezcurvature' of the portion:l9zis'substantially made equal to that of. they fillet I3. The remainingecontour :of ring: I5, that is,.surface s;20;"2 I, and", in Figure 3,

and the filleti "bead 26-closed thereon. I

may be so arranged with intermediate curved parts 23, that a symmetrical contour is provided.

In such case, any 'of the four surfaces can be I placed in contact with the flange II. posed symmetrical surfaces need not necessarily be the same, since, as shown in the embodiment of Figures '7 and 8, two flat surfaces 24 and 25, an

These opintermediate curved surface 26, and an exterior curved surface 2I, may be used, The curved surfacegfi in this case, does not fit snugly into the fillet, but a space mayremain therebetween, so

that all of the side thrust is concentrated on flare I2, rather than distributed between the flare In' Figure '3, the ring is shown prior to being p ace ontheflange, and in an unstretched conbrake drums nowin use. It is sometimes preferable, during the manufacture of a brake drum, to

build therein a' dampener embodying my inven' tion, and for this purpose, the-rubber is applied to the-extreme'end of the flange H which is then upset to form acircumferential bead 2'6 and whichentirely surrounds the rubber ring. Suflicient space H is left between the innermost edge '28'of'the bead 26 and the flange -I i to allow removal of the encaptured 3 rubber ring and "to per-' mit"insertionof a-new ring therebetween. 1 In another embodiment,the'space can be larger or smaller, and even closed altogether; the ring being applied' in the manner described and :then the In Figure 9 ;is-shown a bent-over portion 29 forming a continuation ofthe flare I2, corresponding to certain brake drums now in use, and having'the embodiment of the ring shown in Figure 8 appliedthereto. The'pressure inherent in this ring I5 causes the. material thereof'to be displaced, and" a groove Bil-formedtherein. I l

The rings ,I5j'and I5 are of one continuous piece structure, molded in any manner or by any process well known'to the molders of rubber, adapted to bring about a molecular disposition of the particlescomposing the structure,-so that the action'herein described is carried out. The ringis of course molded so as to have substantially the same consistency and construction throughout its length so' as to form one piece. In certain forms of applicationthis' is not essential, as will be clear 1 from the foregoing, and in sucha case other'primary elements of the invention described, become foremost in'the operation ofthe ring.

I have described herein various embodiments of my' invention, but re'alize'that changes and' modifications may be made therein-without departing from tlie-spirit or scopeof the invention, as de-- finedin the appended claims. 1 m; i 2 .4

l'; A noise dampener for'brake drums comprising a one-piece rubber ring, adapted to be applied to'the'ex terior; of a brake drum, and having ai configurationlthe width of whichis substantially-- equal to its--height and -rela'tively-small in re- V spect to the surface extent inan-axial direction of the flange of the brake drum, and having an internal diameter'le'ssthan the external diameter of the flangeiof the brake drum, and adapted to bestretched'upon saidflange andremainin position thereon the body. of the ring having a thicknessthe flange toprovide for lateral distortion of the ring from the position in which it is placed, to cause a lateral pressure against said flare.

3. A noise dampener for brake drums comprising a ring having an internal diameter less than the external diameter ,of the brake drum flange,

and adapted to be stretched thereon, said ring having a relatively thick .body with'a cross sectional configuration forming a flange contacting straight side, and flare contacting straight side,

all of the sides of the ring being straight and the body being reversible thereby enabling any of the sides to contact with the flange, and the adjacent side of the ring to contact with the flare of the brake drum, and due to the lateral distortion of the ring to exert a lateral pressure upon the flare of the brake drum. 1

4. A noise dampener for brake drumscompris- I ing a ring having an internal diameter less than the external diameter of the flange of a brakedrum and adapted to. be stretched in position thereon, said ring when so stretched distorting itself to bear against the flare of the flange of the brake drum, to exert lateral pressure upon the flare of the flange ofthe brake drum.

5. A noise dampener for brake drums, comprisa a ing a continuous unitary ring having an internal and external diameter, the internal diameter of said ring being smaller than the externaldiameter of the flange of a brake drum, said ring hav-" I ing a width substantially equal to its thickness and held by its own inherent resiliency at any part of the. flange of the brake drum when ing its own inherent resiliencyto distort at least 10 stretched andrplaced thereon, and said ring havone side of the ring to bear towardsthe flare of the flange of the brake drum and exert pres'sural contact upon said flare. e 1 1 6. In a noise dampener for brake drums, the combination of a ring surrounding theflange of the drum, and an extension forming a bead upon said flange circumferentially enclosing said ring.

7. A noise dampener for brake drums, the latter comprising a flange with a flare at one end, said dampener comprising an elastic ring the interior, diameter of which is less than the external diameter of the flange whereby the ring will have a contra ctible tight fit upon the flange to hold a it in place thereon, said ring having a body of substantial thickness distortible to produce an end 'flare for constrictively engaging the end flare ot the flange while'engaging the flange.

SYDNEY G. 'I'ILDEN. 

